The following correction was printed in the Guardian's Corrections and clarifications column, Monday December 18 2006

In the article below we mistakenly listed Maria Callas as one of those whose remains are in the historic Père-Lachaise cemetery in Paris. Her ashes were interred there for a time after her death in 1977 but were taken to Greece and scattered in the Aegean Sea, according to her wish. The empty urn was returned to Paris and is still in the cemetery along with a small memorial.

First Oscar Wilde's tomb was defaced with hundreds of lipstick kisses. Then Jim Morrison's grave had to be protected by a full-time security guard from fans who had painted arrows on other tombs pointing the way "to Jim".

Now the Père-Lachaise cemetery in Paris, where famous residents such as Molière, Marcel Proust, Edith Piaf and Maria Callas attract 2 million visitors a year, has been the victim of theft.

Six bronze busts were stolen last month from its 19th century tombs, including that of Georges Bizet, the composer of Carmen.

The busts dated from the second half of the 19th century and were made by well-known artists of the time. Each is worth between €5,000 and €10,000.

The Paris city hall, which oversees the oldest cemetery in the French capital, has lodged an official complaint with police, Le Parisien reported yesterday.

"It's the work of an expert," a source familiar with the case told the newspaper. The source added that the robberies were probably carried out to order for a collector.

Hugues de Bazelaire, who works on the restoration of funeral monuments, said there was a thriving black market in pieces from French graveyards.

Jean-Claude Hitz, a trade union representative for Paris cemetery workers said that although efforts had been made to provide security for the Père-Lachaise, "20 or so wardens were not enough ... at a site whose five gates are open to the public, where the landscape is hilly and where someone can hide behind a cross or a tombstone, out of sight".